B-locus (coat colour brown, chocolate, ...)

Characteristic and trait of inheritance

There are two alleles: the dominant full color (B) and the recessive brown (b) which is also known in some breeds as liver, chocolate, sedge, and less frequently, red. Two copies of brown are needed to dilute black pigment to brown. For red or yellow dogs, the brown allele does not dilute the hair color, but will change the colour of nose and foot pads from black to brown if two brown alleles (b/b) are present.
This test analyzes whether an animal has 0, 1 or 2 copies of the mutations typically responsible for brown. There are three primary "b" mutations that are responsible for nearly every liver or chocolate dog. A notable exception is the French Bulldog where in addition to these three mutations, there is a fourth cause of chocolate that has yet to be identified.


All breed

Test duration

3-5 days after arrival of the sample in the lab


The DNA test is performed out of EDTA blood or buccal swabs. Required swabs can be ordered free of charge. (Buccal swab order-form). If a swab is sent in, possibly the genetic material is not sufficient to run the test. In this case it would be best to send in an EDTA blood sample.

Testing procedure

Please send in your sample together with the lab order genetic. Results will be transmitted optionally via post, fax or email. After completion of the test you will receive a separate invoice. Payment can be made via credit card or bank transfer.
Breeding club discounts apply if a copy of the membership card is sent together with the respective samples. Due to administrative reasons the invoiced price can not be altered subsequently.


Please contact our molecular biology team for further questions.

Steubenstraße 4
D-97688 Bad Kissingen

Telefon: +49 (0)971 72020
Fax: +49 (0)971 68546
E-Mail: info@labogen.com


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